Senior Network Engineer

Job Description:

DTN is seeking an experienced, hands-on Senior Network Engineer for a project/contract engagement supporting enterprise network infrastructure projects and day-to-day network operations.

In this role, you will lead and execute complex network infrastructure initiatives involving network migrations, cloud networking, F5 load balancing, enterprise firewalls, routing and switching, and ongoing network infrastructure support. You will work across on-premises data centers, wide area networks (WAN), Internet connectivity, and cloud environments to maintain secure, reliable, and highly available enterprise network services.

The ideal candidate brings 10+ years of enterprise network engineering experience, expert-level knowledge of F5 BIG-IP, strong routing and firewall expertise, and a proven ability to lead infrastructure projects from technical design through implementation and operational handoff.

This position requires technical leadership, detailed implementation planning, cross-functional coordination, and advanced operational troubleshooting. You will take ownership of assigned projects, proactively identify technical dependencies and risks, develop comprehensive implementation and rollback plans, and execute network changes with minimal business disruption.

Alongside project delivery, you will support daily enterprise network operations, incident response, maintenance, troubleshooting, and service reliability. The successful candidate must effectively balance project commitments with operational priorities and participate in a rotating on-call schedule, including scheduled after-hours support.

• Design, configure, administer, maintain, and troubleshoot F5 BIG-IP environments, with a strong emphasis on Local Traffic Manager (LTM).
• Manage virtual servers, pools, pool members, health monitors, iRules, persistence profiles, network address translation (NAT), and related application delivery configurations.
• Troubleshoot complex application connectivity issues involving load balancers, enterprise firewalls, network routing, DNS, SSL/TLS, and backend application services.
• Support high-availability configurations, failover testing, software upgrades, and platform migrations.
• Implement, maintain, and troubleshoot SSL offloading and certificate-related configurations.
• Plan and execute F5 migrations, including application dependency analysis, configuration migration, testing, validation, and production cutover activities.
• Support F5 Distributed Cloud (F5 XC) implementations and migrations, including transitions of services from F5 BIG-IP to F5 Distributed Cloud where applicable.
• Ensure application delivery solutions meet enterprise requirements for availability, reliability, performance, and operational continuity.

• Design, implement, maintain, and troubleshoot enterprise Layer 2 and Layer 3 network infrastructure.
• Configure, administer, and troubleshoot routing protocols, including Border Gateway Protocol (BGP), Open Shortest Path First (OSPF), and Enhanced Interior Gateway Routing Protocol (EIGRP).
• Manage route redistribution, routing policies, and complex network routing configurations.
• Support Cisco routers and switches, including Cisco Nexus platforms where applicable.
• Troubleshoot virtual local area networks (VLANs), trunking, Spanning Tree Protocol (STP), inter-VLAN routing, and complex Layer 2/Layer 3 connectivity issues.
• Analyze network routing paths, infrastructure dependencies, and traffic flows to support application migrations and network changes.
• Implement routing and switching changes required for infrastructure migrations, cloud connectivity, and network upgrades.
• Support network resiliency, redundancy, fault tolerance, and high-availability designs.

• Configure, administer, maintain, and troubleshoot enterprise firewall platforms, particularly Palo Alto Networks and Cisco ASA/Firepower.
• Develop, implement, and validate firewall policy changes, NAT rules, virtual private network (VPN) configurations, and high-availability configurations.
• Support firewall migrations, including rule conversion, policy cleanup, configuration validation, and verification of security controls.
• Analyze firewall policies, traffic logs, and session flows to identify and resolve network connectivity and application access issues.
• Collaborate with information security teams to ensure network changes comply with established security requirements and change management standards.
• Support Palo Alto Panorama for centralized firewall administration, policy management, and deployment.
• Maintain secure and reliable connectivity across enterprise network environments while minimizing operational risk.

• Design, implement, support, and troubleshoot network connectivity between on-premises data centers and cloud environments, particularly Amazon Web Services (AWS), Oracle Cloud Infrastructure (OCI), and Microsoft Azure.
• Support cloud networking architectures involving AWS Virtual Private Clouds (VPCs), Azure Virtual Networks (VNets), and OCI Virtual Cloud Networks (VCNs).
• Configure and troubleshoot cloud subnets, route tables, routing configurations, and network security controls.
• Configure, maintain, and troubleshoot cloud routing, site-to-site VPN connections, AWS Direct Connect, Azure ExpressRoute, and OCI FastConnect.
• Support AWS Transit Gateway and equivalent cloud routing architectures.
• Analyze and troubleshoot cloud security groups, network access control lists (NACLs), cloud firewall policies, and routing dependencies.
• Lead or support the migration of applications and network services from on-premises data centers to cloud environments.
• Troubleshoot end-to-end application connectivity across data centers, WAN infrastructure, Internet connections, firewalls, load balancers, and cloud platforms.
• Coordinate with cloud, infrastructure, application, and security teams to support reliable hybrid network connectivity.

• Support daily operations of enterprise network infrastructure across data centers, corporate locations, WAN, wireless networks, Internet connectivity, and cloud environments.
• Monitor network health, availability, performance, and capacity, proactively identifying and resolving issues before they affect business-critical services.
• Troubleshoot and resolve network incidents involving routers, switches, firewalls, load balancers, wireless infrastructure, routing protocols, and cloud connectivity.
• Provide advanced technical escalation support for complex network issues, collaborating with other IT teams to restore services and minimize business impact.
• Perform routine network maintenance, configuration changes, software upgrades, security updates, and hardware lifecycle activities.
• Manage network change requests, including impact assessments, implementation planning, testing, documentation, and post-change validation.
• Support and troubleshoot BGP, OSPF, EIGRP, VLANs, Layer 2/Layer 3 connectivity, firewall policies, NAT, VPNs, and F5 load-balancing services.
• Review network monitoring alerts, logs, performance metrics, and traffic flows using tools such as SolarWinds, NetBrain, or equivalent monitoring and troubleshooting platforms.
• Participate in incident management, root cause analysis, problem management, and corrective action implementation to prevent recurring issues.
• Maintain accurate network diagrams, device inventories, configuration documentation, operational procedures, and troubleshooting records.
• Collaborate with telecommunications carriers, service providers, technology vendors, and internal IT teams to resolve connectivity and infrastructure issues.
• Balance ongoing operational responsibilities with assigned infrastructure projects, maintaining day-to-day network reliability while meeting project milestones and delivery timelines.

• Own assigned network infrastructure projects from requirements gathering and technical design through implementation, validation, and operational handoff.
• Develop comprehensive technical designs, implementation plans, project schedules, migration runbooks, cutover plans, and detailed rollback procedures.
• Identify technical dependencies, assess implementation risks, and establish appropriate mitigation strategies before executing changes.
• Coordinate project resources and technical activities across application, server, security, cloud, infrastructure, and external vendor teams.
• Lead technical implementation meetings, maintenance-window activities, migration cutovers, and post-implementation reviews.
• Communicate project status, risks, technical dependencies, implementation issues, and recommendations to technical stakeholders and management.
• Maintain accurate network diagrams, configuration records, application dependency maps, and project documentation.
• Ensure assigned project deliverables are completed within established timelines and meet technical, security, and operational requirements.
• Plan and execute network changes with appropriate validation, rollback readiness, and minimal disruption to business services.

• Participate in a rotating on-call schedule supporting business-critical enterprise network infrastructure.
• Respond to critical network incidents and technical escalations outside normal business hours, including evenings, weekends, and holidays as scheduled.
• Support planned after-hours maintenance windows, infrastructure upgrades, network migrations, and emergency changes.
• Troubleshoot and resolve production network issues, coordinating with internal IT teams, service providers, and technology vendors as necessary.
• Follow established incident response, escalation, change management, and communication procedures to minimize business disruption and support timely service restoration.

Enterprise Network Engineering Experience

• 10+ years of hands-on network engineering experience within enterprise environments.
• Proven experience designing, implementing, maintaining, and troubleshooting complex enterprise network infrastructure.
• Demonstrated ability to support day-to-day operations of a large enterprise network while simultaneously delivering infrastructure projects.

F5 Load Balancing and Application Delivery

• Expert-level hands-on experience with F5 BIG-IP Local Traffic Manager (LTM).
• Deep knowledge of F5 virtual servers, pools, pool members, health monitors, iRules, persistence, SSL offloading, NAT, and high-availability configurations.
• Experience performing F5 software upgrades, platform migrations, and complex application connectivity troubleshooting.

Routing, Switching, and Network Security

• Strong routing and switching expertise, including BGP, OSPF, EIGRP, route redistribution, VLANs, STP, and Layer 2/Layer 3 troubleshooting.
• Hands-on experience administering and troubleshooting Cisco routing and switching infrastructure.
• Strong enterprise firewall experience with Palo Alto Networks and/or Cisco ASA/Firepower.
• Experience implementing firewall policy changes, NAT, VPN configurations, high availability, and firewall migrations.
• Ability to troubleshoot complex network and application connectivity issues across multiple networking, security, and infrastructure layers.

Cloud Networking and Hybrid Connectivity

• Practical cloud networking experience with AWS, OCI, and/or Microsoft Azure.
• Experience troubleshooting end-to-end application connectivity across on-premises networks, cloud platforms, firewalls, load balancers, and related infrastructure.
• Ability to assess complex network routing and connectivity dependencies across hybrid enterprise environments.

Infrastructure Projects and Operational Delivery

• Demonstrated ability to develop technical designs, implementation runbooks, migration cutover plans, and rollback procedures.
• Proven ability to coordinate complex infrastructure projects across multiple technical teams and external service providers.
• Experience with network monitoring, change management, incident management, and operational documentation.
• Strong incident response, troubleshooting, problem-solving, and root cause analysis skills.
• Ability to prioritize operational incidents, maintenance activities, and project commitments in a dynamic enterprise environment.
• Excellent communication skills, including the ability to clearly explain technical issues, implementation risks,